Norcia: Italy`s most powerful earthquake in 36 years struck a new blow to the country`s seismically vulnerable heart Sunday, terrifying residents for the third time in nine weeks and flattening a revered 600-year-old church.

The national civil protection agency said there had been extensive damage to many historic buildings but no fatalities had been registered some five hours after the quake.

"I can confirm that there are no victims (deaths). Around 20 people are injured. As far as people are concerned, the situation is positive but many buildings are in a critical state in historic centres and there are problems with electricity and water supplies," the agency`s chief, Fabrizio Curcio, said in a lunchtime update.

The quake struck at 7:40 am (0640 GMT) near the small mountain town of Norcia, unleashing a shock felt in the capital Rome, where the metro was partially shut down, and even in Venice, 300 kilometres (200 miles) away.

It measured 6.6 on the so-called moment magnitude scale, according to US geologists, while Italian monitors estimated it at 6.5.

It was Italy`s biggest quake since a 6.9-magnitude one struck the south of the country in 1980, leaving 3,000 people dead.

"We are going through a really tough period," Prime Minister Matteo Renzi said, reiterating a government pledge to rebuild every damaged house and ensure that remote, quake-hit communities are not abandoned.

"We must not allow the profound pain, fatigue and stress that we have now to turn into resignation."Norcia`s 14th-century Basilica of Saint Benedict, built on the reputed birthplace of the Catholic saint, was reduced to rubble.

The church is looked after by an international community of Benedictine monks based in two local monasteries which attract some 50,000 pilgrims every year.

"It was like a bomb went off," said the town`s deputy mayor, Pierluigi Altavilla.
"We are starting to despair. There are too many quakes now, we can`t bear it anymore."

Visibly upset, some of the monks and other residents knelt in prayer before the ruins.

The monks had already launched an appeal to raise $7.5 million to finance repairs to their buildings following damage suffered in the other recent quakes.
Giuseppe Pezzanesi, mayor of Tolentino in the neighbouring Marche region, said the small town had "suffered our blackest day yet".
"The damage is irreparable. There are thousands of people in the streets, terrified, crying. Let`s hope that is an end to it, the people are on their knees psychologically."The quake`s epicentre was located at a very shallow depth of one kilometre (just over half a mile), six kilometres north of Norcia, according to the US Geological Survey (USGS), which measured the magnitude at 6.6.
Italy`s institute of geology and vulcanology (IGNV) measured the quake at 6.5 and said it had been preceded by a 6.1 magnitude shock an hour earlier.
It came four days after quakes of 5.5 and 6.1 magnitude hit the same area and nine weeks after nearly 300 people died in an August 24 quake that devastated the tourist town of Amatrice at the peak of the holiday season.

The 13th-century civic tower in Amatrice, which was damaged but left standing by the August quake, collapsed on Sunday.

As with Wednesday`s tremors, the impact was mitigated by the fact that any buildings deemed vulnerable to seismic activity had been evacuated.

The quake was powerful enough to set off car alarms in Rome, 120 kilometres (75 miles) from the epicentre. Part of the capital`s underground rail network and a road flyover were closed to allow structural safety checks to be carried out.

Much of Italy`s land mass and some of its surrounding waters are prone to seismic activity with the highest risk concentrated along its mountainous central spine.

Italy straddles the Eurasian and African tectonic plates, making it vulnerable to seismic activity when they move.

In addition to the Amatrice disaster in August, just over 300 people perished when a quake struck near the city of L`Aquila in 2009.

In 1980, tremors near Naples left 3,000 dead and an estimated 95,000 died in the 1908 Messina disaster, when a quake in the waters between mainland Italy and Sicily sent massive waves crashing into both coasts.